David Brown was single and on STS-107.

"Benjamin P." wrote:

Is there any program that lets us send singles in to space? Because I
will like to be abele to send some maybe in many years to come some ET
my get the signal may be some one on another planet is doing something
like seti@home is doing. That will be something cool we could do I may
even help seti@home thanks and have a good day.